I. Field of the Invention
The present invention relates to windows and more particularly to impact-resistant and pressure-resistant windows.
II. Description of the Art
Exterior building windows are part of the xe2x80x9cbuilding envelopexe2x80x9d comprising the exterior of the building. As part of the building envelope, exterior windows are subjected to a variety of weather extremes. An increasing number of building code standards and regulations have been, and continue to be, developed for such windows. In particular, many building codes include strenuous impact standards, which require a window to withstand impacts similar to those of a missile driven by high winds, as in a hurricane or a tornado. These building codes may also require the windows to withstand a variety of extreme cyclical pressure changes.
One such standard may be found in Chapters 16 and 24 of the Florida Building Code, Third Draft and in particular xc2xa71626, which requires a window to withstand (1) the impact of an object at high velocity and (2) subsequent cyclical pressure changes. Other building codes have strict requirements for skyscraper windows to reduce the likelihood of implosion or explosion in high winds.
Window manufacturers have developed, and continue to develop a variety of constructions in an effort to meet the evolving building code requirements. Examples of two such constructions are disclosed in U.S. Pat. No. 5,636,484 issued Jun. 10, 1997 to DeBlock and U.S. Pat. No. 5,765,325 issued Jun. 16, 1998 to DeBlock, which share a common disclosure of two embodiments. Both embodiments include a high-strength polycarbonate sheet (1) in the insulated glass assembly and (2) structurally and/or mechanically secured to the window frame. While a significant advance in the art, the development of even-stronger constructions has continued. For example, the most recent code requirements causes the polystyrene window frame to be the likely failure point in the prior construction.
The aforementioned problems are overcome by the present invention wherein an insulated glass (IG) assembly includes a flexible impact-resistant sheet incorporated into the laminated glass, extending beyond the laminated glass, and secured between the frame and the structure to which it is mounted (e.g. a door or a building).
In a preferred embodiment, the frame is injection molded of plastic and is reinforced with high-strength inserts extending between the frame and the glass.
The window unit is extremely strong and is believed to meet all current building code requirements. Further, the window unit is relatively simple and inexpensive.
These and other objects, advantages and features of the invention will be more fully understood and appreciated by reference to the detailed description of the preferred embodiments and the drawings.